Chromium electroplating



Patented Oct. 13, 1953 2,655,471 CHROMIUM ELECTROPLATIN G Allan E. Chester, Highland Park, Ill., assignor to Poor & Company, Chicago, 111., a. corporation No Drawing. Applica Serial N tion December 21, 1951, 0. 262,899

12 Claims. (Cl. 20451) rmium plating baths and to a method for electrodepositing chromium from chromium plating baths.

Still a further object of the invention is to provide a new and improved method for electropear hereinafter.

These objects are accomplished in accordance with this invention by electrodepositing chromium from a chromic acid-sulfuric acid bath trifiuoroacetic acid salt of an oxyalkylated fatty amine. The quantity of the Example I To a chromic acid bath containing 33 ounces gallon of aqueous solution and a having an average molecular weight of 714 (Ethomeen Ferrous metal articles ployed in chromium plating with excellent results.

Example II A chromium plating bath was scribed in Example 2 milliliter of acetic acid salt per gallon of understood that fluoroacetic acid salts of amines may be employed for invention.

other trioxyalkylated fatty the purpose of the acid salts of the oxyalkylclaimed as new compounds in my eopehding pp Serial 262,393, oroacetic acid salt of an oxyalkylated fatty amine filed of even date h r in suflicient amount to retard the liberation of The invention is hereby claimed as follows: chromic i fumes from id bath 1. A chromic acid plating bath for the electrog The method of chromium plating hi d p sit n of h m um tainin a fi comprises electrodepositing chromium from a oroacetic acid salt of an oxyalkylated fatty chromic acid plating t containing a amine in suflicient amount to retard the liberfluoroacetic i h; of an thyl t d f tty ation of chrome acid fumes from Said bethamine in sufficient amount to retard the liber- 2. A chromic acid plating bath for the electroation of chromic acid fumes from said bath. deposition of chromium containing a tr fiuor 9. The method of chromium plating which acetic acid salt of an oxyethylated f y amine comprises electrodepositing chromium from a in sufiicient amount to retard the liberation of chromic acid plating t containing i aqueous chromic acid fumes from said bath. solution 33 to 52 ounces per gallon of CrOs, a 3. A chromic acid plating bath for the electroweight ratio of H2SO4:C1'O3 of 1:100 to 1:60 and d po n of Chromium Containing in aqueous a quantity of a trifluoroacetic acid salt of an solution 33 to 5 Ou per gallon of s, a oxyalkylated fatty amine which exhibits cationic weight ratio of H2SO4ZC1'O3 of 1:100 to 1: 0 and activity in said solution, said quantity of said a q y of a trifiueioaeetie ae'ld Salt of an trifluoroacetic acid salt being suflicient to reoxyalky a f y amino which exhibits cationic tard the liberation of chromic acid fumes from activity in said solution, said quantity of said Said t trifiuoroacetic acid salt being sufiicient to pro- 10, h t d of h i lating which duce a foam blanket on said bath. comprises electrodepositing chromium from a 4. A Chrom a plating bath for the eleetrechromic acid plating bath containing in aqueous d pos ti n of hr m m containing n qu solution 33 to 52 ounces per gallon of 0103, a

solution 33 o 52 ounces per gallon of (Zion, a ratio of HzsOnCrOs of 1:100 to 1:60 and a quanweight ratio of H2SO41C1'O3 f 1 1 0 to 1160 and tity of a trifluoroacetic acid salt of an oxyalkyla qua y of a trifluoroaeetie acid Salt of an ated fatty amine which exhibits cationic activity oxyalkylated f tty a e h c exhibits cationic in said solution, said quantity being within the a tivi y in sa solution, a d a ty being range of /4 to 1 milliliter of the trifluoroacetic within the range of to 1 milliliter of said triacid n; per gallon of Said plating solution fluoroacetic acid salt per gallon of said plating 11 The method of chromium plating which solution. comprises electrodepositing chromium from a 5. A chromic acid p a m ba r the electro chromic acid plating bath containing in aqueous deposition Of chromium contaning in aqueous olution 33 ounces to 52 ounces of Cr0 per galsolution 33 to 52 ounces of ClOs per gallo 9 35 ion of solution, a ratio of H2SO4ICTO3 within solution, a weight ratio of HZSO'iIClOa within t range of ;1 t and a sufficient quanthe ra of 11100 to 1260 and a i nt qllahtity of a trifluoroacetic acid salt of an oxyethYltity of a trifluoroacetic acid salt of an oxyethylt fatty amine containing 1 to 20 0Xyethy1ehe ated fatty amine containing 10 to 20 oxyethy groups per mole of fatty amine and having in 6 gloups P mole of fatty amine and having 40 its alkyl group 8 to 36 carbon atoms to provide in it a y group 3 to 36 carbon atoms to greater throwing power for the chromium in said tard the liberation of chromic acid fumes from bath said bath. 12. The method of chromium plating which 6, A chromic acid plating bath for the eleetrocomprises electrodepositing chromium from a deposition of chromium Containing in aqueous chromic acid plating bath containing in aqueous solution 33 to 52 ounces f s r gallon of solution 33 ounces to 52 ounces of ClOs per Solution, a Weight ratio of 112504101303 Within gallon of solution, a ratio of H2SO4IC1O3 within the range of 11100 to 1160 and e trifiuomacetic the range of 1:100 to 1:60 and a trifluoroacetic acid Sa t o an y y d fatty amine acid salt of an oxyethylated fatty amine containin 0 to 20 y y n groups per mole of taining 10 to 20 oxyethylene groups per mole of amine and having In its group 8 t0 amine and having ts group 8 to 36 carb atoms, the quantity of d salt being 36 carbon atoms, the quantity of said salt being rapproximately milliliter gallon of Said approximately milliliter per gallon of said plating solution. plating solution. '7. The method of chromium plating which comprises electrodepositing chromium from a 55 chromic acid plating bath containing a triflu- No references cited.

ALLAN E. CHESTER. 

1. A CHORMIC ACID PLATING BATH FOR THE ELECTRODEPOSITION OF CHROMIUM CONTAINING A TRIFLUOROACETIC ACID SALT OF AN OXYALKYLATED FATTY AMINE IN SUFFICIENT AMOUNT TO RETARD THE LIBERATION OF CHROMIC ACID FUMES FROM SAID BATH. 